A centrifuge typically comprises a piece of equipment operable to put objects or a process fluid in rotation around a central longitudinal axis. Rotation applies centripetal force to the contents of the centrifuge. Over time, the heavier or denser substances contained therein will settle at the greatest distance from the longitudinal axis. A centrifuge may be used to separate one or more substances from a process fluid.
One useful process making use of a centrifuge is known as classifying. Classifying allows removal of one or more substances from a process fluid as well as separating the different substances from one another. Such classification may be used in a variety of processes (e.g., kaolin classification, cattle product rendering, many food processes, and/or metal recovery).
For example, used drilling mud returning from a well bore may include barite, hematite, or other additives, as well as solids debris from the drill bit or rock, plus water or other fluids used to transport those materials. While the solids debris is unlikely to be of further utility, the barite, hematite, and/or other additives may be used again if they can be separated from the drilling mud and the debris. In addition, the water and/or other transport fluid may be prepared for reuse or environmentally acceptable disposal by removal of one or more substances listed above.
Often, classifying is performed in two or more separate steps, using separate pieces of equipment. An improved classifying centrifuge may provide the same benefit but simplify and/or reduce the maintenance, operation, cost and/or energy consumption over known classifying centrifuges.